Silk screen printing machine



March ll, 1952 G. DUBUIT SILK SCREEN vPRINTING MACHINE 3 Sheets-Sheet l Filed April 5 1951 Ima-unlaw- XM ik Q March 11, 1952 L. G. DUBUIT SILK SCREEN PRINTING MACHINE 5 Sheets-,Sheet 2 Filed April 5 1951 Imaam/baw- DIAN-1x21 March 1l, 1952 l.. G. DUBUIT 'I 2,588,520

SILK SCREEN PRINTING MACHINE Filed April 5, 1951 3 Sheets-Sheet 3 die im@ p2/ZM DMEM GLN-EM Patented Mar. ll, 1952 UNITED STATES yPATENT OFFICE SILK SCREEN PRINTING MACHINE VLouis Gilbert Dubuit, Paris, France Application April 5, 1951, Serial No. 219,389 In France October 4, 11950 8 Claims- 1 The present invention relates to the printing by so-called silk-screen printing process. It is known that this method consists in placing the surface to be printed in contact with a silk screen or stencil the portions of which that do not correspond to the print to be applied having been obturated, then in placing on the stencil an ink or varnish which, by means of a squeegee,

`is caused to pass onto the surfaceto -be printed through the free meshes of the stencil which remained.

This printing method is currently vused for the ornamentation of plane surfaces or of developable surfaces of revolution. Thus, decorations or the like are printed by means of this method onto the at portions. of various articles, on bottles, on glasses or cylindrical or conical cups. However, certain difculties have been met in the use of said method for the printing of circular surfaces such as the surface of plates, saucers or dishes. The printing of such surfaces has been operated hitherto by mean of -a substantially circular stencil under which the surface to be printed is applied and a circular movement about an axis passing substantially through the centre of said surface is imparted to the squeegee intended to cause the ink or the varnish to pass through the stencil. When Vusing such a manner of operating, it is possible to reproduce'printings around the centre ofthe surface to be printed but it is, of course, not possible to point the centre of the plate.

The present invention has for its obiect to provide a device which makes it possible to obtain printings extending to all the desired points of a circular surface, including the centre of said surface.

The device according to the invention fundamentally comprises `means for supporting asubstantially horizontal stencil, means for supporting an article to be printed and for bringing the latter into contact with the lower surface of the stencil, 4a squeegee made of flexible material, the length of which is substantially equal to the diameter of the circular surface to be printed on the article, said squeegee being supported by a vertically rigid but horizontally flexible member, guiding means for bringing the squeegee to the shape of an arc of .circle corresponding toa portion. of ,the periphery Of the surfacetobe printed, means for holding fast one .of the ends of the squeegee supporting member, means for causing ,the squeegee to passte a position which .is

.symmetrical to the starting position of said squeegee with respect to the diameter of the sur- (Cl. .lol-.126)

lface to be printed which passes beneath the 1end of the squeegee which isheld fast, .and meansgfor causing the other end of the squeegee supporting member to simultaneously describe anarc of circle corresponding to the periphery ofthe surface to be printed while passing throughapoint which is diametrically opposedto saidend which is held fast.

The squeegee supporting vmember .preferably consists of a chain formed of linkspivotally ksecured to one another by means of vertical axles. said axles each carrying at their lower .end a fastening member for the squeegee. Oneof ,the ends of said supporting Vrmember may thus be pivotally secured yt0 .a `memberiixed with respect tothe stencil support ,and the other end may be pivotally secured to acrank or like member car.-

ried by a shaft rotatably mounted perpendicularly to the plane of the lstencil `above .the centre of the latter.

The guiding means for thesqueegee may kconsist of two discs having substantially the same `diameter as the ,surface which is to beprinted,

said discs being fastened Aon yboth lsides of the squeegee supporting member and .in ythe s ame Vhorizontal planeas said supporting member, on

a support Capable 0f swinging alQlmd 2.1.1 .aXS

Vperpendicular to the said Vhorizonta1A plane. Ameans being provided in order to impart -to said support areciprocal rocking movement.

The device according to ,the invention will be more Vvfully described lhereunder `with reference totheaccompanving drawingsin which:

Fig. 1 is a vertical sectional View of an embodiment of such ,a device the members supporting v,the stencil being removed and the stencil `vonly being shown in chain dotted lines in its supporting and lguiding means.

'Referring now to the drawing, the device was yshown comprises a base l onwhich is-jplaceda .driving motor A2 -andin which are fastened jthree vertical Vcolumns supporting the devi. Viz- 'za vcoluxnn' vin the rear part of base I land two'columns 4 on both sides of said base. umns are mounted two supports and 6 forming a casing in the upper part of the device. A vertical shaft 1 is journalled in bearings provided in supports 5 and 6 said shaft being connected in its lower part to the driving motor 2. On said shaft 1 is keyed a sleeve 8 carrying a crown cam` 9. Said cam co-operates with a roller carried at the end of a lever II pivotally mounted at I2 on support 5, the other end of said lever carrying a roller I3 engaging between two collars I4 adjustably keyed on a vertical rod I5 sliding in its lower part in a guiding sleeve I6 carried by base I, and in the neighbourhood of its upper end in a sleeve I1 slidably mounted in support 5. In its upper part, shaft I5 carries a disc |8 for supporting the article to be printed, for example a plate shown in chain dotted lines at I9 in Fig. 1. Disc I8 is provided with a lateral protruding terminating as a fork the prongs of which encompass a vertical column 2| mounted between supports 5 and 6.

A square shaft 22 is slldably mounted in holder 6, axially of rod I5. On the lower end of said square shaft 22 is mounted a crank 23 while the upper end of said shaft carries a finger 24 co-operating with a set screw 25 mounted in holder 6, thereby limiting the stroke of said shaft 22 downward in holder 6.

Square shaft 22 is provided with a longitudinal bore in which is rotatably mounted a shaft 26 the lower end of which carries a crank 21, said shaft 26 being maintained longitudinally in shaft 22 by means of a collar 28.

The two ends of the squeegee supporting members are respectively secured on cranks 23 and 21. Said members comprise a chain made of links 29 each of which is pivotally secured to the following by means of a tube 30 crimped at its ends and into which extends an axle 3| which terminates at its lower part in a support 32. A rubber squeegee 33 is clamped in support 32 by means of a counter-plate 34 secured by a screw 35. Axles 3| are maintained in tubes 30 by means of a screw 36. In the linking bore of each terminal link of the so formed chain 29 is arranged On said cola tube 31 which is provided in its lower part with a collar 31a and the upper end of which is externally screw-threaded. Screwed onto said externally screw-threaded part is a member 38 provided with a collar 39 extending through a slot 40 provided in crank 23, said member 38 being secured in said slot 40 by means of a locking nut 4I. Inside tube 31 is arranged an axle 3Ia terminating in its upper part in an externally screw-threaded stud 42 on which is screwed a locking screw 43. Axle 3Ia. extends in lits lower part ina support 32a similar to supports 32 carried by shafts 3| and provided with a counterplate 34a secured by means of a screw 35a and holding the ends of squeegee 33.

A sleeve 44 is freely rotatably mounted on col- -umn 2| and longitudinally held on said column by means of a collar 45. Said sleeve 44 is fast with two arms 46 and 46a supporting at their ends a circular segment 41 in which are provided two arcuate slots 48 and 48a. Secured to arm 46 is .a lever 49 provided with a longitudinal slot 50 in which is secured the linking trunnion 5| of one freely rotatably mounted on column 3 and lon- 4 gitudinally held on said column by means of a collar 51. Two rollers 60 and 60a co-operating with a cam 6I keyed on driving shaft 1 are rotatably mounted on a lever 58 and a member 59 which are both fast with sleeve 56. Fastened in slots 48 and 48a of sector 41 by means of a screw-threaded stud 62, 62a and of a nut 63, 63a respectively are two discs 64, 64a having substantially the same diameter as the circular surface which is to be printed, minus the thickness of the chain 29. The unit formed of the above described members is so arranged that discs 64 and 64a are substantially level with the middle transversal plane of links 59 when square shaft 22 is in its lower position.

Engaging a lateral notch 65 provided in square shaft 22 is a roller 66 rotatably mounted at one end of a lever 61 linked at 68 in support 6, the other end of said lever 61 carrying a roller 69 which co-operates with a crown cam 10 keyed on driving shaft 1.

Sleeve I1 carries at its upper end a disc 11 provided on its upper face with, for example, three stirrups such as 18 regularly distributed around said disc. Engaging between each of said stirrups and disc 11 is a roller 18a carried by one of the arms 19 of an angle-lever pivoted at on a lap fast with disc I8, the other arm 3| of said angle-lever engaging a notch 82 provided on the periphery of disc I8. Arm 8| of each said levers carries a set plate 83, said plates 83 serving to center the article to be decorated on disc I8.

With disc 11 may also co-operate a roller 84 mounted at the end of an arm 85 of an anglelever pivoted at 86 on disc I8, the other arm 81 of said angle-lever terminating in a fork 88. Engaging said fork is a roller 89 carried by one of the arms 90 of an angle-lever pivoted at 9| on disc I8, the end of the other arm 92 of said lever carrying a roller 93 on which rests the end of a rod 98 slidably mounted in an axial bore provided in column 2 Resting on the other end of said rod is a roller 99 carried by an arm |00 of an angle-lever pivoted at |0| in holder 6. Pivotally secured to the end of the other arm |02 of said angle-lever is a link |03 the other end of which is linked on a nger |04 rockingly mounted at |05 on holder 6 and acted upon by a return spring |06. Said finger |04 ends in a nose |01 adapted to co-operate with a lateral stop |08 carried by lever 61.

Two arms I I0 are fastened on columns 4 of the machine by means of an adjustable sleeve |09. Said arms I0 support a frame I (Figures 4 and 5) formed, in the chosen example, of a ring having the general shape of a conical frustum provided with two lateral ears |I2 adapted to be b olted on arms I|0. The silk stencil I|3 is stretched in said frame in a manner known per se in order to make it possible to transfer the desired printing to the article to be printed, said stencil being maintained by means of a string ||4 engaged in a circular groove provided in the periphery of frame III.

The outline of the various cams 9, 6|, 6Ia and 10 forming part of the composition of the machine results from the operation of said machine as shall be described hereafter.

Initially, rod I5 is lowered as a result of the cooperation between lever II and cam 9 and square shaft 22, on the contrary, is raised as a result of the co-operation between lever 61 and cam 10. Sleeve I1 rests on support 5. On the other hand, due to the co-operation between cam 6I and roller 60, discs 64 Vand 64a. occupy the positions shown at Fig. 6. Stencil IIB being fed with varnish by any means known per se, motor 2 is started and a plate IS is laid on disc I B. Owing to the rotation of shaft cam 9 acting on lever II causes said lever to rock in the direction which raises rod i5 and drives plate I9 towards the stencil. Stirrups 'i3 carried by disc 'I1 and acting on levers 'IQ-BI cause plates 83 to rock towards the centre of disc I8, thus cen.- tering plate I9. As the rising movement of rod I5 and disc I 8 continues, disc 'Il is raised by levers lil- 8| which are held fast owing tothe clamping of plates 33 against the edges of plate I9. Fig. l shows the various parts of the machine in the course of this movement of general rising. At the beginning of saidfmovement discs I6 and 1l are spaced apart from each other in such a manner that lever 85 carrying roller 84 which rests on disc 1'! is raised to a position which maintains rod 93 upward, said rod thus driving back lever |04 by means of lever |00- |02 and of link |03 against the action of spring |06, and nose Iii'i being thus released from stop |08 carried by lever 6l'. During said movement, discs IS and ll move slightly away fromeach other, lever 35-81 rocks while leaving rod 98 free to move slightly downward but by a quantity which is insuiiicient for allowing nose |01 to come back on the path of stop |08. VSimultaneously, cam '10 cofoperating with roller G9 carried by lever 6l causes the rocking of said lever 67 in the direction which causes the downward sliding of square shaft 22. Squeegee 33 comes to rest on stencil I3 which is by construcq tion suiiiciently loose to come to apply against the bottom of the plate to be printed.

Cam 6| which rotates with shaft 'I then causes discs 64 and 64a to pass from the position shown at Fig. 6 to that shown at Fig. 8. At the beginning of said movement the chain formed of links 29 rests against disc 64a and follows, therefore, as well as squeegee 33 carried by said chain, a fraction of the periphery of the bottom of the plate which is to be printed, on one of the sides of said bottom. During the above mentioned movement of discs 64 and 64a, disc 64 presses against the chain formed of links 29 and drives it back while causing the rotation of crank 21 fast with shaft 26 which rotates freely inside square shaft 22. The whole surface of the stencil corresponding to the bottom of plate I9 is thus swept by squeegee 33, the linking axle 3|a of the end of the chain on crank 2l describing a circle having the same radius as said bottom i while passing through the intermediary position .shown at Fig. 7 in which the chain formed of Alinks 29 is stretched along a straight line coinciding with a diameter of plate I9. When discs `6 4 and 54a arrive to the extreme position shown at Fig. 8, cam 9 causes the rocking of lever 14 in a reverse direction to that which had taken place previously and rod I5 is lowered. As the lowering movement of shaft I5 continues, sleeve II is stopped in its stroke `by support 5 and, rollers 18a then resting on disc TI, levers Ill-8| rock while releasing the printed plate I9. Said plate is then removed, a new plate is laid on disc I8 and the same sequence of operations is repeated. During the next operative sequence, discs 64 and 64d pass back from the position shown at Fig. 8 to'that shown at Fig. 6.

It may vbe seen that during the transfer operation the whole surface of the bottom of the plate has been swept and lthat the described machine 'E 5 therefore makes it possible to print any desired decoration even at the centre of the plate.

In case the operator handling the plates should omit, during the operation of the machine, to place a plate on disc I8 in due time, the rocking of levers 'IS-8| caused by the increase of the distance between discs I8 and 'Il' would be continued beyond that which normally takes place when plates S3 come to rest against the edges of a plate laid on disc I8. The spacing between discs. I8 and l? would then become large enough for rod 98 to be lowered by the action of levers 85-81 and S30-432, thereby allowing nose |01 of lever |04, acted upon by spring |06, to come on the path of stop |03. Lever 61 would be held fast in spite of the fact that roller 69 is released by cam 'I3 thus impeding the lowering of square shaft 22. In this manner, squeegee 33 cannot be brought into contact with stencil I|3 and during the sweeping movement carried out by said squeegee, the latter cannotcause the passage of the ink or varnish throughv the stencil, thus avoiding the spoiling of disc I8.

The described machine can be used for the transfer of any decorations on plates, dishes, saucers or like articles with a circular, substantially plane surface and of any diameter under the condition that chains 2a are available the lengths of which are equal to the diameters of the surfaces which are to be printed.

Said chains of various lengths may beset in the desired position owing to the slots provided in cranks 23 and 27. Discs 64 and 64a corresponding to the desired diameter and plates 83 having the desired size or shape in order to encompass the article to be printed should also jbe available. If necessary, it is also possible to change disc I 6 with the levers which it carries for adapting it tothe size and shape of the article tc be printed. All these modications can be carried out readily and rapidly when the necessary spare parts are available. The strokes of rod I5 and of square shaft 22 can also be modified by moving collars I4 and screwing or unscrewing set screw 25 for adapting said strokes to the thickness of the article to be decorated.

What I claim is:

1. In a silk screen printing device for printing on a circular surface of an object, a silk- 1 screen stencil, means for supportingsaid stencil in a substantial horizontal plane, means for supporting the object to be printed and means for applying the circular surface of said object which is to 'ce printed under said stencil, a iiexible squeegee cooperating with said stencil, the length of said squeege-e being substantially equal to the diameter of said circular surface, horizontally flexible and vertically rigid supporting means for said squeegee, having approximately the 'same length as said squeegee, means for holding one end of said squeegee supporting means at a xed point above the periphery of said circular surface in the` object supporting means, means for guiding the other end of said squeegee supporting means along a part of the periphery of said circular surface, extending on both sides of a point diametrically opposed to the above mentioned `fixed point, and means Yfor causing said squeegee to take an arcuate position following part of the periphery of said circular surface and to pass from said position to a symmetrical position with respect to the diameter of said cir.- cular surface which passes through the vabove mentioned fixed point.

2. In a silk screen printing device for printf.-

ing on a circular surface of an object, a silkscreen stencil, means for supporting said stencil in a substantially horizontal plane, means for supporting the object to be printed and means for applying the circular surface of said object which is to be printed under said stencil, a exible squeegee cooperating with said stencil, the length of said squeegee being substantially equal to the diameter of said circular surface, horizontally exible and vertically rigid supporting means for said squeegee, having approximately the same length as said squeegee, a supporting member carried by the stencil supporting means and holding one end of said squeegee supporting means, at a fixed point above the periphery of said circular surface inthe object supporting means, a rotatable shaft arranged vertically above the center of said circular surface inthe objectv supporting means and above the screen, a crank arm extending laterally from said rotatable shaft and rigidly connected to said rotatable shaft, means for securing the other end of said squeegee supporting means on said crank arm, at a distance of the axis of said shaft substantially equal to the radius of said circular surface, and means for causing said squeegee to take an arcuate position followingpart of the periphery of said circular surface and to pass from said position to a symmetrical position with respect to the diameter of said circular surface which passes through the above mentioned xed point.

3. In a silk screen printing device for printing on a circular surface of an object, a silkscreen stencil, means for supporting said stencil in a substantially horizontal plane, means for supporting the object to be printed and means for applying the circular surface of said object which is to be printed under said stencil, a flexible squeegee cooperating with said stencil, the length of said squeegee being substantially equal to the diameter of said circular surface, horizontally flexible and vertically rigid supporting means for said squeegee, having approximately the same length as said squeegee, a rod arranged vertically above the center of said circular surface in the object supporting means, said rod being longitudinally, slidably mounted in a support rigid with the stencil supporting means, but incapable of rotating in said support, an arm extending laterally from said rod, m-eans for securing one end of said squeegee supporting means on said arm, an axial boring in said rod, a shaft rotatably mounted in said boring and axially fixed with respect to said rod, a crank arm extending laterally rom said rotatable shaft and rigidly connected to said rotatable shaft, means for securing the other end of said squeegee supporting means on said crank arm, at a distance of the axis of said shaft substantially equal to the radius of said circular surface, and means for causing said squeegee to take an arcuate position following part of the periphery of said circular surface and to pass from said position to a symmetrical position with respect to the diameter of said circular surface which passes through the above mentioned fixed point.

4. In a silk screen printing device for printingI on a circular surface of an object, a silkscreen stencil, means for supporting said stencil in a substantially horizontal plane, means for supporting the object to be printed and means for applying the circular surface of said object which is to be printed under said stencil, a :dexible squeegee cooperating with said stencil, the

length of said squeegee being substantially equal to the diameter of said circular surface, a chain formed of links connected to one another by means of vertical trunnions, the lower ends of said trunnions being arranged to support said squeegee, whereby a horizontally exible and vertically rigid supporting means are provided for said squeegee, said chain having approximately the same length as said squeegee, means for holding one end of said chain at a xed point above the periphery of said circular surface in the object supporting means, means for guiding the other end of said chain along a part of the periphery of said circular surface, extending on both sides of a point diametrically oposed to the above mentioned fixed point and means for causing said squeegee to take an arcuate position following part of the periphery of said circular surface and to pass from said position to a symmetrical position with respect to the diameter of said circular surface which passes through the above mentioned fixed point.

5. In a silk screen printing device for printing on a circular surface of an object, a, silkscreen stencil, means for supporting said stencil Iin a substantially horizontal plane, means for supporting the object to be printed and means for applying the circular surface of said object which is to be printed under said stencil, a flexible squeegee cooperating with said stencil, the length of said squeegee being substantially equal to the diameter of said circular surface, a chain formed of links connected to one another by means of vertical trunnions, the lower ends of said trunnions being arranged to support said squeegee, whereby a horizontally flexible and vertically rigid supporting means are provided for said squeegee, said chain having approximately the same length as said squeegee, a rod arranged vertically above the center of said circular surface in the object supporting means, said rod being longitudinally, slidably mounted in a support rigid with the stencil supporting means, but incapable of rotating in said support, an arm extending laterally from said rod, means for adjustably securing one end of said chain on said arm, an axial boring in said rod, a shaft rotatably mounted in said boring and axially xed with respect to said rod a crank arm extending laterally from said rotatable shaft and rigidly connected to said rotatable shaft, means for adjustably securing the other end of said chain on said crank arm, and means for causing said squeegee to take an arcuate position following part of the periphery of said circular surface and to pass from said position to a symmetrical position with respect to the diameter of said circular surface which passes through the above mentioned fixed point.

6. In a silk screen printing device for printing on a circular surface of an object, a silk-screen stencil, means for supporting said stencil in a substantially horizontal plane, means for supporting the object to be printed and means for applying the circular surface of said object which is to be printed under said stencil, a exible squeegee cooperating with said stencil, the length of said squeegee being substantially equal to the diameter of said circular surface, horizontally flexible and vertically rigid supporting meansfor said squeegee, having approximately the same length as said squeegee, means for holding one end of said squeegee supporting means at a fixed point above the periphery of said circular surface in the object supporting means, means for guiding the other end of said squeegee supporting means along a part of the periphery of said circular surface, extending on both sides of a point diametrically opposed to the above mentioned fixed point, a fork-like member having two branches extending one on each side of said squeegee supporting means and rotatably mounted on a vertical shaft, a circular member arranged on each said branches of said fork-like member in the same horizontal plane as the gf' squeegee supporting means, the diameter of said circular member being substantially equal to that of said circular surface, said circular member being centered on a circular line passing above the center of said circular Surface and the center of which is on the axis of said vertical shaft of said fork-like member, and means for communicating a reciprocating movement to said forklike member about said vertical shaft.

'7. In a silk screen printing device for printing on a circular surface of an object, a silk-screen stencil, means for supporting said stencil in a substantially horizontal plane, means for supporting the object to be printed and means for applying the circular surface of said object which is to be printed under said stencil, a flexible squeegee cooperating with said stencil, the length of said squeegee being substantially equal to the diameter of said circular surface, a chain formed of links connected to one another by means of Y vertical trunnons, the lower ends of said trunnions being arranged to support said squeegee, whereby a horizontally exible and vertically rigid supporting means are provided for said squeegee, said chain having approximately the nected to said rotatable shaft, means for adjustably securing the other end of said chain on said crank arm, a fork-like member having two branches extending one on each side of said chain and rotatably mounted on a vertical shaft, a circular member arranged on each said branches of said fork-like member, in the horizontal mean plane of said chain, the diameter of said circular member being substantially equal to that of said circular surface, said circular member being centered ori a circular line passing above the center of said circular surface and the center of which is on the axis of said vertical shaft of said forklike member, and means for communicating a reciprocating movement to said fork-like member about said vertical shaft.

8. In a silk screen printing device for printing on a circular surface of an object, a silk-screen stencil, means for supporting said stencil in a substantially horizontal plane, means for supporting the object to be printed and means for applying the circular surface of said object which is to be printed under said stencil, a flexible squeegee cooperating with said stencil, the length i of said squeegee being substantially equal to the diameter of said circular surface, a chain formed of links connected to one another by means of vertical trunnons, the lower ends of said trunnions being arranged to support said squeegee, whereby a horizontally flexible and vertically rigid supporting means are provided for said squeegee, said chain having approximately the same length as said squeegee, a rod arranged vertically above the center of said circular surface in the object supporting means, said rod being longitudinally, slidably mountedy in a support rigid with the stencil supporting means, but incapable of rotating in said support, an arm extending laterally from said rod, means for adjustably securing one end of said chain on said arm, an axial boring in said rod, a shaft rotatably mounted in said boring and axially fixed with respect to said rod a crank arm extending laterally from said rotatable shaft and rigidly connected to said rotatable shaft, means for adjustably securing the other end of said chain on said crank arm, a fork-like member having two branches extending one on each side of said chain and rotatably mounted on a vertical shaft, a circular ff member arranged on each said branches of said fork-like member in the horizontal mean plane of said chain, the diameter of said circular member being substantially equal to that of said circular surface, said circular member being centered on a circular line passing above the center of said circular surface and the center of which is on the axis of said vertical shaft of said forklike member, a driving motor, a shaft driven by said motor, a first cam on said shaft, arranged for communicating a reciprocal movement to said fork-like member about its shaft, and a second cam on said motor driven shaft, cooperating with a lever attached to the above mentioned vertically slidable rod.

LOUIS GILBERT DUBUIT.

No references cited. 

